[pve-devel] [RFC qemu-server 2/9] cfg2cmd: improve error message for invalid volume storage content type

[Daniel Kral]

Thank you very much for taking a look over this!

Sorry for taking such a long time for getting back to you on this, I'll 
rework this patch series for a v2 now.

On 11/29/24 15:23, Fiona Ebner wrote:
> Am 16.09.24 um 18:38 schrieb Daniel Kral:
>> diff --git a/PVE/QemuServer/Helpers.pm b/PVE/QemuServer/Helpers.pm
>> index 0afb6317..9d0f24aa 100644
>> --- a/PVE/QemuServer/Helpers.pm
>> +++ b/PVE/QemuServer/Helpers.pm
>> @@ -106,6 +106,51 @@ sub vm_running_locally {
>>       return;
>>   }
>>   
>> +=head3 check_storage_content_type($storecfg, $storeid [, $content_type])
> 
> Usually, "assert_" rather than "check_" is used for such helpers that
> die upon failing the check, so maybe "assert_content_type_supported"
> 
> Nit: there is no blank line below the header when viewed with perldoc

Hm, I'm sure it's possible but a quick glance over some other perldocs 
showed me that other perldocs don't seem to add a blank line below the 
function signature either (I looked at `AnyEvent::HTTP` and 
`Archive::Cpio` specifically, but they also seem to not follow the 
`head3` as we do).

Do you have a reference that I can see how documentation should be 
formatted?

> 
> I'd rather have the content type be non-optional. And actually, the
> helper should live in the storage library, because it doesn't depend on
> anything outside it.

I agree, I'll make it required and move all other storage-related 
helpers to `PVE::Storage` too (which you pointed out) as it makes much 
more sense to have them there.

> 
>> +
>> +Checks whether the storage with the identifier C<$storeid>, that is defined in C<$storecfg>,
>> +supports the content type C<$content_type>. If the C<$content_type> is undefined, it will default
>> +to the value C<"images">.
>> +
>> +If the check fails, the subroutine will C<die> with an error message containing the storage and
>> +content type that is not supported.
>> +
>> +Returns C<1> if the check is successful.
>> +
>> +=cut
>> +
>> +sub check_storage_content_type : prototype($$;$) {
>> +    my ($storecfg, $storeid, $content_type) = @_;
>> +
>> +    $content_type = "images" if !defined($content_type);
>> +    my $scfg = PVE::Storage::storage_config($storecfg, $storeid);
>> +    die "storage '$storeid' does not support content type '$content_type'\n"
>> +	if !$scfg->{content}->{$content_type};
>> +
>> +    return 1;
>> +}
>> +
>> +=head3 check_volume_content_type($storecfg, $volid)
> 
> assert_volume_content_type_supported
> 
> should/could also live in the storage library

ACK

> 
>> +
>> +Checks whether the volume with the identifier C<$volid>, that is defined in C<$storecfg>, supports
>> +the content type, which is determined by L<PVE::Storage::parse_volname>.
>> +
>> +If the check fails, the subroutine will C<die> with an error message containing the storage and
>> +content type that is not supported.
>> +
>> +Returns C<1> if the check is successful.
>> +
>> +=cut
>> +
>> +sub check_volume_content_type : prototype($$) {
>> +    my ($storecfg, $volid) = @_;
>> +
>> +    my ($storeid) = PVE::Storage::parse_volume_id($volid);
>> +    my ($vtype) = PVE::Storage::parse_volname($storecfg, $volid);
>> +
>> +    return check_storage_content_type($storecfg, $storeid, $vtype);
>> +}
>> +
>>   sub min_version {
>>       my ($verstr, $major, $minor, $pve) = @_;
>>